20 research outputs found
Glass Transition of Hard Sphere Systems: Molecular Dynamics and Density Functional Theory
The glass transition of a hard sphere system is investigated within the
framework of the density functional theory (DFT). Molecular dynamics (MD)
simulations are performed to study dynamical behavior of the system on the one
hand and to provide the data to produce the density field for the DFT on the
other hand. Energy landscape analysis based on the DFT shows that there appears
a metastable (local) free energy minimum representing an amorphous state as the
density is increased. This state turns out to become stable, compared with the
uniform liquid, at some density, around which we also observe sharp slowing
down of the relaxation in MD simulations.Comment: 5 pages, 5 figure
Enhanced stability of layered phases in parallel hard-spherocylinders due to the addition of hard spheres
There is increasing evidence that entropy can induce microphase separation in
binary fluid mixtures interacting through hard particle potentials. One such
phase consists of alternating two dimensional liquid-like layers of rods and
spheres. We study the transition from a uniform miscible state to this ordered
state using computer simulations and compare results to experiments and theory.
We conclude that (1) there is stable entropy driven microphase separation in
mixtures of parallel rods and spheres, (2) adding spheres smaller then the rod
length decreases the total volume fraction needed for the formation of a
layered phase, therefore small spheres effectively stabilize the layered phase;
the opposite is true for large spheres and (3) the degree of this stabilization
increases with increasing rod length.Comment: 11 pages, 9 figures. Submitted to Phys. Rev. E. See related website
http://www.elsie.brandeis.ed
The Proton Spin and Flavor Structure in the Chiral Quark Model
After a pedagogical review of the simple constituent quark model and deep
inelastic sum rules, we describe how a quark sea as produced by the emission of
internal Goldstone bosons by the valence quarks can account for the observed
features of proton spin and flavor structures. Some issues concerning the
strange quark content of the nucleon are also discussed.Comment: 59 pages with table of contents, Lecture delivered at the Schladming
Winter School (March 1997), to be published by Springer-Verlag under the
title "Computing Particle Properties" (eds. C. B. Lang and H. Gausterer